Current pulser technology utilizes pulsers that are sensitive to different fluid pump down hole pressures, and flow rates, and require field adjustments to pulse properly so that meaningful signals from these pulses can be received and interpreted uphole.
An important advantage of the present disclosure and the associated embodiments is that it decreases sensitivity to fluid flow rate or pressure within easily achievable limits, does not require field adjustment, and is capable of creating recognizable, repeatable, reproducible, clean [i.e. noise free] fluid pulse signals using minimum power due to a unique flow throttling device [FTD] with a pulser that requires no guide, guide pole or other guidance system to operate the main valve, thus reducing wear, clogging and capital investment of unnecessary equipment as well as increasing longevity and dependability in the down hole portion of the MWD tool. This MWD tool still utilizes battery, magneto-electric and/or turbine generated energy. The mostly unobstructed main flow in the main flow area enters into the cone without altering the main flow pattern. Without the mudscreen obstructing the main flow area there is no reduction in the differential pressure so that the original orifice opening (area and volume) and the cone geometry (area and volume) causes a restriction in flow leading to a large differential in flow rate leading to a larger associated pressure differential (as described in the Bernoulli equation). The increased flow rate and change in pressure produces a very efficient pilot valve response and associated energy pulses. Specifically, as the pilot valve closes faster (than in any known previous designs) this produces a water hammer effect much like that is heard when shutting off a water faucet extremely quickly. The faster flow and corresponding larger pressure differential also moves the pilot valve into an open and closed position more rapidly. The faster the closure, the more pronounced the water hammer effect and the larger the pulse and associated measured spike associated with the pulse. These high energy pulses are also attributed to the position and integrity of the pilot channel seals (240) which ensure rapid and complete closure while maintaining complete stoppage of flow through the channel. The controllability of the pulser is also significantly enhanced in that the shape of the pressure wave generated by the energy pulse can be more precisely predetermined. The pulse rise and fall time is sharp and swift—much more so than with conventional devices utilizing guide pole designs. These more easily controlled and better defined energy pulses are easily distinguished from the background noise associated with MWD tools. Distinguishing from the “background” noise leading to ease of decoding signals occurring on an oil or gas rig offers tremendous advantages over current tools. Being able to control and determine pulse size, location, and shape without ambiguity provides the user with reproducible, reliable data that results in reduced time on the rig for analysis and more reliable and efficient drilling. It is estimated that each work day on a rig, on average, amounts to more than 1 million US dollars, so that each hour saved has extreme value.